DARPA's New TERN, a Predator on a Frigate

The US Navy has operated unmanned aircraft from warships since Gyrodyne QH-50 drones carried anti-submarine torpedoes off the flightdecks of destroyers in the 1960s. But they have either been big ships (Pioneers on battleships) or small UAVs (ScanEagles on destroyers). No-one wants to recover a 55ft-wingspan MQ-1 Predator by flying it at a net or catching it on a rope.

Now DARPA wants to enable small ships such as the 2,800-ton Independence-class Littoral Combat Ship to launch and recover Predator-class medium-altitude, long-endurance UAVs. The Tactically Exploited Reconnaissance Node (TERN) program seeks to demonstrate a MALE UAV, and associated automated launch and recovery system, that can carry a 600lb payload 600-900nm from its host vessel.

Concept: DARPA

The normal approach to operating a large aircraft from a small deck – a helicopter – won’t work, says DARPA, because their range and endurance is limited. The MQ-8B can fly 110nm, and stay on station 5hr carrying a 600lb payload. The larger Bell 407-based MQ-8C will increase endurance to 11hr with a 600lb payload, but that is still well short of what DARPA envisions for TERN. Abe Karem designed the A160 Hummingbird to be the unmanned-helicopter equivalent of a Predator, and on paper it looks good, but Boeing has struggled to turn it into a reliable aircraft.

TERN is planned to be a three-phase, 40-month program culminating in a full-scale launch and recovery demonstration. In addition to launch and recovery, endurance and payload, DARPA says key technical challenges include packaging the system to fit into the limited space available with minimal, preferably reversible, ship modifications and minimal requirements for additional personnel.